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Caption

Skin disorder. Close-up of the arm of a patient showing many benign pigmented naevi, also known as moles. Moles are brown to dark brown in colour and may be of different sizes. They are caused by abnormality or overactivity of melanocytes, the skin cells which produce the brown pigment melanin. Most naevi are harmless and do not require any treatment. However, if a naevus suddenly grows, bleeds or becomes lumpy medical advice may be needed to exclude the possibility of the form of skin cancer known as melanoma.